# status.ludic — RPG Module G: status effects over the shared combat backbone (#59).
#
# A status is its own small entity (like a gameplay Modifier), so an actor can carry
# any number and world_save captures them. esys_status ticks each on its interval,
# routing poison/regen through the ludic.gameplay Combat pipeline (so armor, veto
# and Died all still apply), and expires it. Timed stat buffs/debuffs are already
# ludic.gameplay modifiers (Stats.modify with a ttl); this module adds the
# over-time damage/heal effects.
#
# kind: 0 poison (damage over time), 1 regen (heal over time).

import "ludic.gameplay/combat.ludic"

enum StatusKind { Poison, Regen }                # Status.apply kind
property Status { target: int = 0, kind: int = 0, amount: int = 0, interval: int = 30, ttl: int = 0, t: int = 0 }
model StatusFx { Status }
@OnSpawn(StatusFx) handler StatusFxInit { }

event StatusApplied { target: int = 0, kind: int = 0 }
event StatusExpired { target: int = 0, kind: int = 0 }

# Status.apply(target, kind, amount, interval, ttl) — attach a timed effect.
@Namespace(Status) function status_apply(target: int, kind: int, amount: int, interval: int, ttl: int) -> int {
  let m = World.model_id("StatusFx")
  if m < 0 { return -1 }
  let e = World.spawn(m)
  let P = World.prop_id("Status")
  World.set(e, P, World.field_id(P, "target"), target)
  World.set(e, P, World.field_id(P, "kind"), kind)
  World.set(e, P, World.field_id(P, "amount"), amount)
  World.set(e, P, World.field_id(P, "interval"), interval)
  World.set(e, P, World.field_id(P, "ttl"), ttl)
  World.set(e, P, World.field_id(P, "t"), interval)
  emit StatusApplied(target: target, kind: kind)
  return e
}
# Status.clear(target) — drop every status on an actor (dispel).
@Namespace(Status) function status_clear(target: int) -> void {
  let P = World.prop_id("Status")
  if P < 0 { return }
  let ft = World.field_id(P, "target")
  var e = World.query_next(P, 0)
  while e >= 0 {
    var nxt = World.query_next(P, e + 1)
    if World.get(e, P, ft) == target { despawn e }
    e = nxt
  }
}

# ===========================================================================
# esys_status (Update) — tick intervals, apply the effect through Combat, expire.
# ===========================================================================
@EngineSystem(Status, Update) function esys_status() -> void {
  let P = World.prop_id("Status")
  if P < 0 { return }
  let ftgt = World.field_id(P, "target")
  let fkind = World.field_id(P, "kind")
  let famt = World.field_id(P, "amount")
  let fint = World.field_id(P, "interval")
  let fttl = World.field_id(P, "ttl")
  let ft = World.field_id(P, "t")
  var e = World.query_next(P, 0)
  while e >= 0 {
    var nxt = World.query_next(P, e + 1)
    let tgt = World.get(e, P, ftgt)
    let kind = World.get(e, P, fkind)
    let amt = World.get(e, P, famt)
    # interval tick
    var t = World.get(e, P, ft) - 1
    if t <= 0 {
      if kind == 1 { Combat.heal(tgt, amt) } else { Combat.damage(tgt, tgt, amt) }
      t = World.get(e, P, fint)
    }
    World.set(e, P, ft, t)
    # lifetime
    let ttl = World.get(e, P, fttl) - 1
    if ttl <= 0 { emit StatusExpired(target: tgt, kind: kind);  despawn e } else { World.set(e, P, fttl, ttl) }
    e = nxt
  }
}